An analysis by the Agency for Healthcare Research and Quality of automated claims data from nearly 930 000 enrollees in 10 geographically diverse health plans over a 30-month period reveals that more than 40% of patients received at least one medication that carried a black box warning that could potentially apply to them.
Physicians were less likely to comply with the warning recommendations when patients did not receive necessary laboratory tests before beginning new prescriptions. However, high levels of physician compliance were found when drugs were prescribed for pregnant women, and there was almost no coprescribing of contraindicated drugs with QT-interval-prolonging drugs that regulate heart rhythm.
Hampton T. Black Box Warnings. JAMA. 2006;295(4):377. doi:10.1001/jama.295.4.377-c